Author -> Geike De Sloover
# Overview
In this step, we correct any missing points in each individual tree
point cloud in RiSCAN PRO using the QGIS crown‐hull map. The process
covers:
- Loading your project and QGIS map
- Identifying and isolating a single tree point cloud
- Adding missing trunk or branch points
- Saving the corrected tree point cloud
- Exporting all corrected point clouds at the end
Intermezzo - Quote of the Notebook
“To see the forest in 3D, one must scan every tree.”
— Overly poetic TLS researcher
Methods
1. Load the Project and QGIS Map
- Open your RiSCAN PRO project and the QGIS project you created in
02_prep.
- In RiSCAN PRO, display all point clouds (individual
trees + leftover) in single‑color mode.
- Color the leftover cloud in a distinct hue (e.g., dark maroon or
height‑based coloring) so it stands out.
- Click the “bird” (top‑down) view icon to align your screen with the
QGIS map.

- Based on the QGIS map and the point clouds, select your target tree.
In the following example the green tree was chosen as the target tree.
Thanks to the QGIS hull map, it was easy to figure out that it is tree
number 369460_8074920_08.


- If necessary, change the colours of the point clouds for good
visibility. In this example, the leftover point cloud colour was changed
to height‐above‐ground (blue shades) and the target tree to bright
yellow.
2. Isolate a Single Tree
Select an area that fully encloses the target
tree (including any missing bits).
Now you have two options:
- (NEW!) Lock the target
tree (the lock icon) and click Show Selected (arrow on
image).
It will show only the selected area while the
locked tree will stay selected (red colour).
- Other option:
- Click Show Selected (arrow on image), alas, you
forgot to lock the tree beforehand… :(
- In the Object Inspector, lock the target tree (the
lock icon)—this won’t affect the next steps but makes it easy to re‑find
the tree.
- Go to Point Clouds in the Object Inspector,
right‑click and choose Hide All. Everything will
disappear from the view.
- Find your locked tree (golden lock icon), unlock it, then click the
cloud symbol to Show it.

- Use the selection tool to select the target tree.
- Once done, in Object Inspector, right‑click Point Clouds →
Show All to show the surrounding area again.
Now the target tree is selected, with its surrounding area
visible.

3. Add Missing Pieces
- Apply the Height Filter (image below, indicated
with red arrows).
- Starting at the bottom of the target tree, go through the tree
looking for missing parts.

- Select the missing trunk sections, large branches, or other missing
features.
- You can skip isolated floating points or very small twigs unless
they affect height or crown area.
- Make sure to select the full butresses of trees as they are often
cut off.
- We chose to not add epiphytes or lianas growing on the trees to the
individual tree pointclouds. If needed and possible you can segment
those out (sometimes the difference between epiphytes and crown will not
be clear, in that case you can leave them).
- For example: The darker red branches were missing and
selected.

- When finished scanning from bottom to top, click Show
Selected.
- Inspect your selection for mistakes (e.g., stray points from
neighboring trees).
- It’s often faster to include extra points and then remove outliers
in this step.
- For example: the points circled in red will be removed later.

4. Save the Corrected Tree Point Cloud
- Once finished, select the full tree.

- With your full‑tree selection active, click Copy Selection
with Filter Settings (cloud icon dropdown).
- In the dialog:
- Enable “Move to new file” (not “Copy To”)
- Enable “Combine data”
- Rename the point cloud to the correct tree ID (output name)
- Ensure all point attribute options are
selected

- Click OK, then Show All to restore
the full project view.
